GPS

A U.S. owned utility providing users with precise positioning, navigation, and timing (PNT) services via a constellation of 24+ satellites.

Global Positioning System (GPS) operates through a baseline constellation of 24 satellites orbiting 12,550 miles above Earth, broadcasting continuous radio signals. Managed by the U.S. Space Force, these satellites enable receivers in everything from iPhones to Boeing 787s to calculate location within centimeters using trilateration. Beyond simple navigation, the system provides nanosecond-accurate timing essential for synchronizing global financial markets, power grids, and 5G cellular networks.

https://www.gps.gov